This study will attempt to correlate plasma lipoprotein changes induced by cholsterol-rich diets with the development of accelerated atherosclerosis in various animal models. Characterization of cholesterol-induced lipoproteins in dogs, swine, monkeys, rats, and rabbits has shown that various species have similar metabolic responses to increased dietary cholesterol. The hyperlipoproteinemia has certain consistent features, including the occurrence of beta-very low density lipoproteins, an increase in low density lipoproteins, and the appearance of a unique lipoprotein, HDLc. The occurrence in increased concentration of a specific apoprotein (the arginine-rich apoprotein, apo-E) with all these cholesterol-induced lipoproteins suggests an important role for this protein in cholesterol metabolism and possibly in accelerated heart disease. The various animal lipoproteins are being compared to purified human plasma lipoproteins.